Ground-based flight trainers or flight simulators have been in use in the aviation field for many years and their value has been amply proven. Generally, there are considered to be two generic forms of simulations, engineering simulation and training simulation. Engineering simulation in one which attempts to recreate a condition as faithfully as possible to achieve an evaluation of engineering factors. Consequently, such simulation attempts to achieve as high a fidelity of reproduction of the condition as possible. Training simulation, on the other hand, is designed to facilitate initial skill acquisition as well as proficiency maintenance and the degree of fidelity required for such simulation has been the subject of scientific inquiry. Concerning this inquiry, there has existed for some time a belief that the greater the fidelity of a simulation for training purposes, the greater the training effectiveness. Thus, for the most part, currently utilized trainers are highly elaborate and complex and, consequently, are available only at relatively high cost. Requisite expenditures for their utilization, therefore, usually are justified only by larger user entities, i.e. commercial aviation, government or larger corporate aircraft owners. For such organizations, these higher costs become justified where a sufficient quanta of pilot performance learned in the trainer transfers to adequate performance in a corresponding aircraft. This has been found to be the case with respect to commercial aviation, somewhat elaborate simulators having been found to lower the cost of pilot training in transitioning from one aircraft model to another or in maintaining skills. For example, where pilots have been required to spend an average of approximately twenty hours of in-flight training to transition to a new aircraft, with the advent of simulation, this requirement has been gradually reduced by a factor of five to ten for a variety of aircraft types. While the pilots are required to spend approximately the same number of hours in training, the total time required is actually reduced by reasons of the greater availability of simulators and the elimination of much of the preparation time. The safety factors associated with the elimination of much of the in-flight training time, the release of aircraft for revenue flights and decreased cost of operating a simulator rather than an aircraft for training have provided adequate cost justification for the larger users operating in conjunction with experienced pilots. See in this regard:
1. "Visual Elements in Flight Simulation", Brown, Aviation Space and Environmental Medicine, Vol. 47, September 1976, pp. 913-924. PA1 2. Creelman, J. A., Evaluation of Approach Training Procedures. Pensacola, Fla.: U.S. Naval School of Aviation Medicine, Report Number 2, 1955. PA1 3. Young, L. L., Jensen, R. S., and Treichel, C. W., Use of a Visual Landing System in Primary Flight Training. Proceedings of the 17th Annular Meeting of the Human Factor Society, Santa Monica, Calif.: Human Factors Society, 1973. PA1 4. Hasbrook, A. H., The Approach and Landing: Cues and Clues to a Safe Touchdown, Business and Commercial Aviation, Nov. 1975, pp. 39-43. PA1 5. Department of Civil Aviation. Flight Instructor's Manual: Melbourne, Australia: Lintern, Publication Number 45, 1967.
While the cost of simulator training is justified in case of pilot qualification for large, complex aircraft, it has been considered prohibitive for applications in general aviation. Given such justification, however, ground-based training facilities would play an important role in primary training within the general aviation field as well as commercial fields. Such simulator training would be of particular advantage in the more difficult phases of flight. In the latter regard, learning to land an airplane represents one of the most difficult phases of training. See in this regard:
The landing phase of aircraft flight, also, is one of the most dangerous, and after pilot training, remains so even for experienced pilots. See:
It has been opined that poor definition of important visual cues or the imprecision of the information gained from such cues contributes substantially to the difficulties of learning approach and landing of an airplane. Generally, pilot proficiency in landing maneuvers depends upon perceptual judgments that must be acquired primarily by repetitive practice that is both time consuming and often frustrating, the novice pilot executing repeated landing and takeoff maneuvers being required to expend about six minutes in circling and flying the downwind leg and, of course, such maneuvers also affect control tower operations. By providing a trainer with a final (straight-in) approach and land capability, the novice pilot may execute this most important maneuver with considerable rapidity. Further, the instructor may stop the maneuver at any point and provide explanation of erroneous procedures and the like. For a more detailed discussion, see the following publications:
Computer generated visual information systems have been developed for a broad range of aircraft training simulation applications. While the majority of such systems have been generated for utilization in the more elaborate installations, for example, use in evolving the visual cues of varied locations with night terrain, developments also have been witnessed in the generation of such visual cue systems for less elaborate installations. One such system is described in British patent specification 1446334 wherein a video readout of specific visual terrain cues is provided at the windscreen of a fixed-base training cockpit. The system serves to associate the controls of the cockpit, an electonic logic assembly or computer and the video readout to achieve a visual training simulation. The electromics associated with such computerized systems are called upon to generate by analogue technique a view of simulated terrain with a six degree of freedom capability, for example, signals representative of latitude and longitude, altitude, heading and the attitudes of pitch and roll. The electronic components required to accommodate these six variables are somewhat extensive, the computer components of such prior systems being required to perform cosine-related analogue transformation logic, a task which is quite complex electronically and involves concomitant cost considerations. Additionally, cues other than visual are not available with the system, i.e. motion generated cues associated with, for example, pitch and roll.
Another aspect of visual cue effectiveness concerns the requisite development of visual perspective or depth perception. This perception is developed both by virtue of the parallax of the human visual structure and by the projected shape of the runway. While the latter is the major factor developing this perspective, in trainers, should that shape appear at the training cockpit windscreen, then a perspective conflict arises between the shape perspective and binocular parallax effect. To accommodate for this, the elaborate training installation usually employ mirror system to project the virtual image to infinity. While this optical correction is effective, it remains costly, prohibiting its use in the general aviation trainers now contemplated.
Some investigators have considered that the interactions between the visual system, the proprioceptive system and the vestibular system are of importance. In this regard, it has been considered by some that visual motion in the absence of corresponding physical motion does not evoke a satisfactory cue for training purposes. Physical motion has for some time been incorporated in training devices including those suited for general aviation but not incorporating visual cues and utilized for more experienced pilots in developing instrument navigational capabilities. The motion cue components developed for the more elaborate aircraft trainers operate on the basis that the accelerations of the initiation of a motion pattern are duplicated, but decelerated below the threshold for motion detection before the mechanical limits of the simulator are reached. This technique of "washing out" the motion has been considered a successful motion cue. Since humans sense acceleration but not constant velocity, a reasonable solution to the motion simulation problem is achieved within practical cost limitations. For a more detailed discourse concerning the above, reference is made to publication 1 above.
From the foregoing, it may be observed that a need exists for a flight simulator trainer system which can provide both visual and motion cues and which will serve as an effective trainer for the final approach and flare out to landing procedures for aircraft. Further, such a device is needed which is economical to the extent that it can be utilized for training pilots in the general aviation field where severe training cost constraints are present.